Method for applying adhesive to cross threads while crosslaying

ABSTRACT

A method for applying adhesive to the cross threads in a thread crosslaying apparatus is disclosed. The cross threads served by a carrier rotating around an elongated medium moving helically around a mandrel are drawn over the face of an adhesive applicator located between the mandrel and the carrier. The spacing and continuity of adhesive applied to the cross threads is governed by the number, size and shape of the openings in the adhesive applicator and the relative speed and direction of rotation of the applicator relative to the carrier.

METHOD FOR APPLYING ADHESIVE TO CROSS THREADS WHILE CROSSLAYING Filed May 2l, 1969 3 Sheets-Sheet l July 18, 1972` K. E. sAGER 3,677,854

METHOD FOR APPLYING ADHESIVE T0 CROSS THREADS WHILE CROSSLAYING .Tiled May 2l, 1969 V3 Sheets-Sheet 2 wwf/ms? /J MPX aya/ff July 18, 1972 K. E. sAGER 3,677,854

METHOD FOR APPLYING ADHESIVE TO CROSS THREADS WHILE CROSSLAYING Filed May 2l, 1969 .3 Sheets-Sheet 3 www.:

United StatesPatent Oce 3,677,854 METHOD FOR APPLYING ADHESIVE T CROSS THREADS WHILE CROSSLAYING Karl E. Sager, Appleton, Wis., assignor to Kimberly- Clark Corporation, Neenah, Wis. Filed May 21, 1969, Ser. No. 826,390 Int. Cl. B65h 81/02 U.S. Cl. 156-173 7 Claims ABSTRACT OF THE DISCLOSURE A method for applying adhesive to the cross threads in a thread crosslaying apparatus is disclosed. The cross threads served by a carrier rotating around an elongated medium moving helically around a mandrel are drawn over the face of an adhesive applicator located between the mandrel and the carrier. The spacing and continuity of adhesive applied to the cross threads is governed by the number, size and shape of the openings in the adhesive applicator and the relative speed and direction of rotation of the applicator relative to the carrier.

BACKGROUND OF TI-IE INVENTION The present invention relates generally to the fabrication of nonwoven materials more particularly concerns a method for applying adhesive to the cross threads in a thread-type crosslaying apparatus.

It has previously been proposed, for example in Hirschy Pat. No. 2,841,202 and in Burger Pat. No. 3,025,196, to provide thread crosslaying apparatus for making non- Woven material in which the longitudinally extending warp threads are coated with adhesive and bonded to the generally transversely extending cross threads at their crossings. While such a nonwoven scrim has utility of its own it is often necessary to add till adhesive at least to the cross thread side of the scrim in order to more permanently bond the cross threads to the warp threads or to other materials laminated to the scrim. This results in both the warp and cross threads being coated with adhesive over substantially their entire lengths and this requires the application of more adhesive than is actually necessary to adequately bond the respective components together.

Accordingly, it is the primary aim of the present invention to provide a method for applying adhesive to the cross threads in a crosslaying apparatus in controlled manner.

It is a more specific object of the invention to provide such a method which permits the application of adhesive to the cross threads in either a continuous or discontinuous manner and to precisely locate the discontinuous pattern of adhesive at selected points along the cross threads` such as only adjacent the edges of the crosslaid web or only at certain thread crossing points.

Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. l is a schematic perspective view of a thread type crosslayer embodying apparatus which may be utilized to practice the method of the present invention.

FIG. 2 is an enlarged fragmentary saide elevation of the crosslaying apparatus with the cross thread adhesive applicator shown in retracted position;

FIG. 3 is a further enlarged partial section through the thread crosslayer and adhesive applicator; the latter being shown in its operative position by full lines; its retracted position by dash lines; and an alternative operative position by dot-dash lines; and,

FIGS. 4 and 5 are enlarged partial sections through the 3,677,854 Patented July 18, 1972 thread crosslayer and adhesive applicator taken at right angles to the section of FIG. 3 showing two diiferent patterns of openings in the adhesive applicator.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Turning now to the drawings, there is shown schematically in FIG. 1 a thread-type crosslaying apparatus 10 employing cross thread adhesive applicating apparatus embodying the present invention. The illustrated apparatus 10 includes a generally cylindrical mandrel 11 around which an endless belt 12 is helically wound through a plurality of turns. The mandrel 11 is preferably in the form of a hollow cylindrical shell having a plurality of air discharge openings 13 (see FIGS. 35) through which air supplied to the interior of the mandrel passes to oatingly support the belt 12 on the surface of the mandrel.

In the present instance, the belt 12 makes three turns or wraps on the mandrel 11 and the belt is further supported by a plurality of guide rollers and turning bars 14-19 mounted in a suitable frame (not shown). It will be understood that the location and disposition of the roller 14 relative to the mandrel 11 determines the approach angle of the belt 12 to the mandrel and thus the angle of the helical turns. The roller 15 serves not only to guide and support the belt 12 as it moves off the mandrel, but also drives the belt around the helical turns through suitable drive means (not shown). The belt is also guided by rollers 16 and 19 and turning bars 17 and 18, the latter of which are preferably of the air oating type, as the belt returns from drive roll 15 to guide roll 14.

Fed onto the belt 12 are a plurality of warp threads 20 which are drawn from respective supply spools located, for example, in a creel room 21. The threads pass through a comb 22 to align them in spaced-apart, substantially parallel relation. In the illustrated apparatus the threads 20 are then drawn over a grooved adhesive applicator roll 23 which, at least, partially coats the threads with a .thin layer of exible adhesive. The applicator roll 23 is partially submerged in liquid adhesive contained in a supply trough 24 and excess adhesive is removed from the surface of the roll by a suitable doctor blade 25. lf desired the roll 23 may be driven by a motor (not shown) at a peripheral speed slower than the movement of the threads 20 in order to control the amount of adhesive on the threads.

From the adhesive applicator roll 23, the threads are carried into the crosslaying apparatus 10 on the belt 12. In the illustrated embodiment the threads 20 are deposited on the upper surface of a carrier sheet 30 moving into the crosslaying apparatus 10 on the belt 12. The carrier sheet may comprise a web of creped cellulosic wadding drawn from a supply roll 31 and around guide rollers 32 and 33 onto the upper surface of the belt. Desirably the roller 33 is positionedsuch that the web 30 of creped wadding intersects the threads 20 at a slight angle and the adhesive on the threads is suicient tacky to hold the threads on the web surface in the spaced-apart, parallel relationship established by the guide comb 22.

A serving ring 35 is rotated about the mandrel 11 in the direction of the arrow 36 in timed relation to the helical movement of the belt 12 around the mandrel. As the serving ring rotates, a plurality of cross threads 37 drawn from respective supply cones 37a and out through serving eyes 38 are helically wound about the mandrel 11 and belt 12, with the threads 37 disposed in spacedapart, substantially parallel relation and extending generally straight across the web 30 and Warp threads 20 in a transverse direction. The serving ring 35 is journalled in suitable bearings, for example, a plurality of rollers disposed peripherally about the ring in a supporting frame (not shown). A drive motor 39, preferably of the variable speed type, is provided for rotating the ring 35 through a suitable ring gear 39a or the like. The precise spacing of the threads 37 and their angular orientation relative to the web 30, of course, depend upon the number of threads served by the ring 35, the rotational speed of the ring relative to the belt, as Well as the helical angle of the belt.

Following the helical wrapping of the cross threads 37 over the Warp threads 20 on the web 30, another web 40 is preferably introduced in registry with the belt 12 and web 30 and is wound about a subsequent helical turn on the mandrel 11. In the illustrated apparatus 10, the web 40 is drawn from a supply roll 41 and is trained around guide rolls 42, 43 and 44 which guide the web 40 to the mandrel in registry with the belt 12 and web 30 as they travel around the mandrel. The web 40 thus overlies the cross threads 37 and imprisons them against the warp threads 20 and the lower web 30. The top web 40 preferably makes at least one complete helical turn on the mandrel 11 and a slitter 48 is disposed along the edges of the Webs 30 and 40 and belt 12 to cut the cross threads 37 into transverse segments having a length substantially equal to the width of the webs 30 and 40.

After the slitting operation, the belt 12 and composite web comprising the bottom web 30, warp threads 20, cross threads 37 and top web 40 travel oi the mandrel 11 in the direction of the belt drive and support roller 15.The composite web is then separated from the belt 12 and, in the illustrated apparatus 10, is Wound around the surface of a preheat drum 50 before being directed into the nip of a pair of calender rolls 51 and 52. The composite web then passes over a series of cooling drums 53 and 54 prior to being wound up on a take-up roll 55.

In accordance with the present invention, means are provided for selectively applying adhesive to the cross threads 37 prior to their being Wound helically around the mandrel 11. As shown in greater detail in FIGS. 2-5 the cross thread adhesive applicator means includes an adhesive applicator ring 60 mounted concentricallly about the mandrel 11. In its operative position (see FIG. 3) the ring 60 is disposed so that the cross threads 37 are drawn over a rounded face 61 of the ring and wipe adhesive supplied through a plurality of openings 62 from the face of the applicator ring.

Liquid adhesive is applied to an interior cavity 63 within the applicator ring 60 by a suitable pump (not shown) through a conduit 64 connected to a manifold 65. The manifold is open about its outer periphery and is encircled by a channel 66 formed in the inner periphery of the ring which defines a series of openings 67 (only one of which is shown) through which the adhesive passes into the ring cavity 63. By regulating the pressure and viscosity of the adhesive the amount of adhesive issuing through the openings 62 can be suitably regulated.

It is an important feature of the invention that the adhesive can be applied to the cross threads 37 at preselected points. To this end, the openings 62 in the ring 60 may be located and positioned such that adhesive is applied to the cross threads only at points on the threads which will lie adjacent the edges of the webs 30 and 40. Thus, if the ring 60 is stationary, two appropriately positioned openings 62 will apply a small quantity of adhesive at two points on each of the cross threads 37 as they are drawn over the face 6l of the applicator such that these points lie one on either side of the slitter wheel. In this Way the ends of each cross thread can be stabilized and bonded to the composite web with a minimum of adhesive. Additional adhesive points can, of course, be added if desired by simply providing additional openings 62 in the face 61 of the applicator ring.

Another aspect of the invention is the provision for indexing and rotating the applicator ring 60. This is accomplished, in the illustrative embodiment, with a motor 70 coupled to the ring 60 through suitable gears 71 and 72 or the like. By rotatably indexing the applicator ring 60 through a partial revolution, the ultimate location of a spot of adhesive applied to a cross thread 37 can be caused to shift from one side of the composite web to the other. In this way, the adhesive spots applied from two openings 62 can be located so that the slitter 48 passes precisely between them.

By providing the applicator ring with adhesive openings 62 equal in number to the number of warp threads 20 it is possible to apply a spot of adhesive along each cross thread at each point where it will ultimately cross one of the warp threads. Again the provision for rotatably indexing the applicator ring by a few degrees or more permits precise registry ofthe adhesive spots at the thread crossings.

The present invention also contemplates varying the adhesive pattern applied to the cross threads 37 by rotating the applicator ring 60 in the same direction as the ser-ving ring 35 but at a diterent relative speed or by rotating the applicator ring in the opposite direction. Thus with a given number of openings 62 in the face of the ring 60, progressively faster rotation of the applicator ring from zero to the rotational speed of the serving ring will cause a proportionate decrease in the number of adhesive spots along the cross threads 37 with respect to the `width of the web from a number equal to the number of openings to zero. Conversely, opposite rotation of the applicator ring will cause the cross threads to pick up a greater number of adhesive lspots than when the applicator ring is stationary.

The foregoing makes it possible to apply adhesive to the cross threads at points where the cross threads over lie the warp threads even though the number of adhesive openings in the applicator ring 60 differs from the number of warp threads. It will also be appreciated that a substantially continuous coating of adhesive can be applied to the cross threads.

The adhesive pattern applied to the cross threads 37 can also be altered by changing the shape of the openings 62 in the applicator ring 60. As shown in FIG. 4, the openings 62 are small circular openings adapted to apply the adhesive to the cross threads in the form of relatively small spots of adhesive. In the alternative embodiment shown in FIG. 5, the openings 62a are in the form of slots which have a substantial length in the circumferential direction. These slots permit the application of adhesive to the cross threads in the form of a periodic dash pattern along the length of the cross threads.

It is another feature of the present invention that the applicator ring 60 can be axially shifted. For this purpose, a fluid power cylinder 75 or similar linear actuator is provided. In FIG. 2, the applicator ring 60 is shown in its retracted position and in FIG. 3 in its normal operative position. An alternate operative position is also shown in phantom in FIG. 3. In addition to moving the applicator ring 60 between its retracted and operative positions, the actuator 75 permits slight axial shifting of the ring to change the location that the cross threads 37 are laid on the warp threads 20. This makes it possible to not only apply adhesive at discrete points along the length of each cross thread 37, as described above, but also to precisely control the placement of the cross threads along the length of the warp threads.

While the invention has been described herein in connection with certain preferred embodiments and procedures, I do not intend to limit the invention to those specific embodiments and procedures. On the contrary, I intend to cover all such other alternative and equivalent embodiments and procedures as fall within the spirit and scope of the present invention.

I claim as my invention:

1. A method of applying adhesive to cross threads in a thread crosslying apparatus comprising the steps of:

moving an elongated medium helically about a generally cylindrical mandrel;

rotating a carrier concentrically about the mandrel;

serving threads from respective supply cones supported by the rotating carrier as the elongated medium moves helically about the mandrel;

drawing the threads over the face of an adhesive applicator ring independently supported concentrically between the mandrel and the carrier;

supplying liquid adhesive to the face of the applicator at a plurality of points spaced circumferentially around the applicator; wiping adhesive from said spaced points on the face of the applicator with the threads as they are drawn over the face while rotating said carrier relative to the face of said applicator so that adhesive is applied to said threads in a discontinuous manner; and

crosslaying the threads over the elongated medium as it moves helically around the mandrel.

2. The method defined in claim 1 wherein said points are spaced apart such that the adhesive is applied to the threads at locations where the threads overlie the marginal edges of the elongated medium.

3. The method defined in claim 1 wherein said applicator is axially shiftahle to adjust the placement of the threads as they are crosslayed on the elongated medium.

4. The method defined in claim 1 wherein said applica- 6 tor is rotatably adjustable about said mandrel to change the locations of adhesive application on the threads relative to the width of the elongated medium.

5. The method defined in claim 1 wherein said applicator is rotated about said mandrel in the same direction as said carrier but at a different rotational speed.

6. The method defined in claim 1 wherein said applicator is rotated about said mandrel in the opposite direction to the rotation of said carrier.

7. The method dened in claim 1 wherein said elongated medium comprises a plurality of spaced apart warp threads and the adhesive is applied to said cross threads at points where said cross threads are laid across said warp threads.

References Cited UNITED STATES PATENTS 3,025,196 3/1962 Burger 156-426 3,391,043 7/1968 Bascom 156-181 3,023,729 3/1962 Hayden et a1 117--112 CARL D. QUARFORTH, Primary Examiner R. L. TATE, Assistant Examiner U.S. Cl. X.R. 

